The convergence of Internet and wireless telephony through packet-based systems has led to new opportunities as well as new problems. One new opportunity that has emerged is the utilization of an instant messaging-type server in combination with a wireless communication system to provide a group messaging service. A problem that arises in such a service is that users of instant messaging systems can be actively coupled (logged on) to the system or inactively coupled (logged off) at any given time. Thus, a message originator who sends a group message to a plurality of wireless recipients does not have any way of knowing who has received the group message and who has not.